Toe iron for safety ski bindings

ABSTRACT

1,142,169. Toe-iron for safety ski bindings. H. MARKER. 24 May, 1966 [4 June, 1965], No. 23181/66. Heading A6D. A toe-iron for safety ski bindings is characterised by the combination of all the following features: (a) a sole-retaining member is braced through a bearing means, against a guide surface extending transversely to the longitudinal direction of the ski; (b) the length of the guide surface extending transversely to the longitudinal direction of the ski corresponds approximately to the range of foottwist occurring during harmless lateral-jolts; (c) adjacent to the guide face running transversely to the longitudinal direction of the ski are guide faces which are inclined sharply forwardly on both sides, and (d) the soleretaining member is, in every position, subject to the action of one or more return springs. In one embodiment the toe-iron comprises a base part 1 fitted rigidly on the ski; a soleretaining member 2 having a beaded edge 11 which engages over the front edge of the sole, also having flanges 18 and 19 which fit over the projection 15 and is guided and held by bolts 6 and 7 in the groove 3; and a spring element 9 guided and held in part 1 by the bolts 10; the two ends of the spring 9 engage with the sole-retainer 2 via the bolts 6 and 7. The sole-retainer 2 is capable of moving initially only transversely to the longitudinal direction of the ski and to ensure this two guide projections 12 and 13 are provided between the flanges 18 and 19, and are braced against the projection 15. In the extreme pivoted position it is possible for the soleretainer 2 to execute a forward pivoting movement. Other embodiments are described in which (a) the sole-retainer is not a self-contained component but is comprised of two angles which are connected with each other through angle arms; and (b) the sole-retainer is guided longitudinally with respect to the ski in a groove of a sliding block which for its part can only move transversely of the longitudinal direction of the ski, the longitudinal movement of the sole-retainer being governed by the position of the sliding block with respect to the guide face of the housing.

Oct. 24, 1967 H. MARKER ETAL -3,348,854 TOE IRON FOR SAFETY SKI BINDINGS Filed June 1, 1966 4 Sheets-Sheet 1 Oct. 24, 1967 ARKER ETAL 3,348,854

TOE IRON FOR SAFETY SKI BINDINGS Filed June l 1966 4 Sheets-Slmetv 2 62 776.9 73 {5 K 74 I 65 Q,"

Oct. 24, 1967 H. MARKER ETAL 3,348,854

TOE IRON FOR SAFETY SKI BINDINGS Filed June 1, 1966 4 Sheets-Sheet 5 4, 1967 I H. MARKER ETAL 4 TOE IRON FOR SAFETY SKI BINDINGS Filed June 1, 1966 4 Sheets-Sheet 4 United States Patent 3,348,854 TOE IRON FOR SAFETY SKI BINDINGS Hannes Marker, Haupststrasse 5153, Garmisch-Partenkirchen, Germany, and Gunter Adam, Garmisch-Partenkitchen, Germany; said Adam assignor to said Marker Filed June 1, 1966, Ser. No. 554,579

Claims priority, application Germany, June 4, 1965,

5 Claims. (Cl. 28011.35)

The invention relates to a safety toe iron which, by exercising a relatively long damping action, absorbs the lateral jolts and more trivial torsion stresses arising during normal progress, only releasing the foot completely under more prolonged lateral or torsion force, whereupon the toe iron or its sole retaining member is restored to the midway position under spring tension, the toe iron returning to its normal position in which it is possible to fit the boot into the binding.

Various types of t-oe iron are known which, to absorb or damp the lateral jolts arising during normal progress, admit of a small to medium pivoting movement before the foot is released when a pre-set torque is exceeded. With these types of binding, a disadvantage is that the toe iron performs a circular movement about an axis disposed at right angles to the surface of the ski and so, looking in the longitudinal direction of the ski, is pushed a little to the rear first, during this pivoting movement, against the tightening force applied towards the point of the ski by the heel, until the rear edge of the supporting surface, looking in the direction of pivoting, has reached the longitudinal centre line. During the further pivoting movement, the foot is then pushed forwardly by the clamping force. Whereas the relatively considerable clamping force impedes the foot being forced backwardly and also the releasing movement, considerable difiiculties arise when a forward displacement of the foot which has already occurred has to be recompensated by the return spring of the toe iron, if the lateral or torsion force which has arisen is not sufiiciently strong for the foot to have to be released. With ski bindings of this type, it often occurs that the foot remained in a midway position in which the longitudinal axis of the foot is oblique to the longitudinal axis of the ski, so that a spill is inevitable.

A further disadvantage of the known toe irons of the aforesaid type resides in that the return spring acts directly as an arresting element, so that, in cases of relatively pronounced rotational movement, the spring becomes necessarily increasingly tighter, so that the resistance of the spring to further pivoting steadily increases. In consequence the resistance of the toe iron to being twisted in the midway position is initially relatively small, so that holding of the foot in the binding is unreliable even in the normal position, an improvement of this hold being impossible in the midway position because the spring can only be pretensed that release is possible in the event of a spill, against the then rapidly increasing resistance of the spring.

The invention is based on the problem of avoiding the disadvantages of the various known toe irons offering damping of lateral forces through a relatively long damping travel. In particular, the invention is intended to provide a toe iron in which the releasing movement and the damping of the forces arising during more trivial lateral jolts can no longer be affected to a considerable extent or even prevented by the clamping force. A further object of the invention resides in constructing a safety toe iron with a damping action in such a way that there is no essential difference in the spring resistance over the entire damping path, so ensuring that instability of the grip in the midway position is avoided. Finally, it is also intended to provide a possibility, in the case of a safety toe iron,

of dispensing with adjustment of the spring force to adapt the toe iron to suit skiers of different weight and skiing habits.

The problem of which the invention is mainly based is resolved by a combination of the following features:

(a) The sole-retaining member is braced through a friction-reducing means, against a guide surface extending transversely to the longitudinal direction of the ski;

(b) The length of the guide surface extending transversely to the longitudinal direction of the ski corresponds approximately to the range of foot-twist occurring during harmless lateral jolts;

(c) Adjacent to the guide face running transversely to the longitudinal direction of the ski are guide faces which are inclined sharply forwardly on both sides, and

(d) The sole-retaining member is, in every position, subject to the action of one or more return springs.

By virtue of the guide face extending transversely to the longitudinal direction of the ski and the fact that this avoids a turn-table mounting of the sole-retaining member means that, in the initial phase of the release movement, the foot does not have to be forced back against the clamping force, on the one hand, and, on the other, that before the actual release, too, no forward guiding occurs under the effect of the clamping force, which cannot be compensated by the return spring of the toe iron. The effect of the clamping force is therefore neutralised for the entire range of pivoting movement until the point of actual release, so that return to the midway position is readily possible in the case of more trivial lateral jolts. On the other hand, the fact that the sole-retaining member, as soon as the parts thereof which are braced against the guide face which extends transversely to the longitudinal direction of the ski have left this guide face, slides with these bracing parts or with the (in the direction of rotational movement) front bracing part, along the sharply forwardly inclined guide face, results in an immediate release of the foot when the range of relatively small and harmless foot twists is exceeded. Since the return springs co-operate with the sole-retaining member in all positions of the latter, damping of more trivial side jolts is guaranteed, together with a return of the sole-retaining member into the midway position after the foot has been released during a spill.

According to a further development of the invention, the spring element can co-operate with the sole-retaining member in such a way that an abutment part of the soleretaining member slides along a lever adapted to pivot against the force of the spring, the shape and arrangement of the lever and the lever arm which extends during displacement of the sole-retaining member compensating for any increase in spring resistance during rotational movement. In another embodiment, the spring element cooperates with the sole-retaining member through a control curve provided on a separate component which guides the sole-retainer, the control curve once again being so contrived that the increase in spring resistance is matched by a corresponding decrease in curve pitch, so that the increase in spring resistance due to increasing tension of the spring is compensated. In a particularly advantageous form of embodiment, the spring element used is a torsion spring, of which the free spring arms act as lever members and co-operate with a corresponding abutment part of the sole-retaining member.

It is an essential feature of all embodiments that a long damping travel is achieved for any lateral forces, ex-

cluding the backwards and forward movement of the shoe, hitherto usual during the rotational movement of rotatably mounted toe irons, as well as the clamping force acting from the heel in the direction of the ski tip. According to the further solution which is proposed according to the invention, lateral movement is counteracted by approximately the same mangnitude-of force in every pivoting position, causing the toe iron to return automatically from any desired position, even from the position of release. By reason of the long damping travel and constant spring resistance, which can it is true be varied at will by appropriate shaping of the cams or levers required to transmit the spring action, it is also possible to dispense altogether with any adjustability of the spring force because, with a very long damping travel and a constant spring resistance, any excessive clamping in the binding, which would prevent release, is avoided; nor need it be feared any longer that an excessively light adjustment of the spring might unintentionally release the foot, as can happen in the case of conventional bindings, with a ball detent arrangement.

A plurality of embodiments of the invention are explained in greater detail in the ensuing description, in which reference is made to the attached'drawings, in which:

F161 is a vertical cross-section through-a first em: bodiment of a toe iron according to the invention;

FIG. 2 is a plan view of the toe iron shown in FIG. 1;

FIG. 3 is a plan view of the toe iron shown in FIGS. 1 and 2, in the released position;

FIG. 4 is a vertical cross-section through a second embodiment;

FIG. 5 is a plan view of the toe iron in FIG. 4;

FIG. 6 is a plan view of the toe iron in FIGS. 4 and 5, in the released position;

FIG. 7 is a verticalcross-section through a third embodiment, taken along the broken line indicated in FIG. 8;

FIG. 8 is a plan view of the embodiment shown in FIG. 7, and

FIG. 9 is a plan View of the embodiment shown in FIGS. 7 and 8, in the released position.

FIGS. 1 to 3 illustrate an embodiment of toe iron according to the invention. The toe iron consists of the part 1 which is to be fitted rigidly on the ski and the soleretaining member 2 having a beaded edge 11 which engages over the front edge of the sole. The sole-retainer 2 has flanges 18 and 19 which fit over the projection 15 on part 1 and is guided and held by bolts 6, 7 in the groove 3 provided in the projection 15. As the spring element, a torsion spring 9 is used which is guided and held in, part 1 by the bolts the two ends of the said torsion spring 9 engage with the sole-retainer 2 via the bolts 6,7. In the case of a force arising transversely to the longitudinal direction of the ski, the sole-retainer 2 can move sideways and, by virtue of the shape of the curve 3, initially only transversely to the longitudinal direction of the ski. In this case, the torsion spring 9 is additionally tensed by displacement of the bolts 6, 7. So that the other end of the spring which now becomes free cannot follow, an abutment 17 is disposed on the fixed part 1, between the two spring ends. As an additional safeguard against tilting and at the same time to relieve the strain on the bolts 6, 7, two guide projections 12., 13, are provided between the two flanges 18, 19, and are braced against the projection 15. Sothat the spring 9 always counteracts the transverse movement of the sole-retainer 2 through the bolts 6 or 7 with a constant force, looking in the transverse direction, care must be taken to ensure that the spring force increasing by bending-together of the torsion spring is compensated by extension of the lever arm or appropriate shifting of the point of attack of the force (6, 7) as can be achieved by a particular shaping of the spring ends in a definite curved form.

In the extreme pivoted position, as shown in FIG. 3, it is possible for the sole-retainer to execute a forward pivoting movement, because the bolts 6 and 7 can move into the forwardly guided ends of the curve, 4 or 5, the corners 20, 21, of the surface being able to move into the recess 14 in the sole-retainer 2. As is also visible in FIG. 3, the spring 9 still, in this position also, remains each other through the angle arms 33, 34 and withthe rigid part 30 through the bolt 32. To permit of sideways movement when forces are generated in the sole-retainer (33, 34, 35, 36), the bolt 32 is guided in the fixed part in a groove 31. In order initially to prevent a tilting movement of the angle arms 33, 34 about the bolt 32, the

angles 35, 36, are braced against the guide face 47 ofthe fixed part 30 through rollers 37, 38 which are mounted in the angle arms 33, 34 by means of pin members 51,

52. Only after a relatively considerable lateral movement can the rollers 37, 38 slide over the lateral oblique faces 48, 49, so that the sole-retainer (33,. 34, 35, 36), is able to pivot about the bolt 32. This position is shown in FIG.

6. By forming the groove 31 as a straight groove and the.

guide face 47 as a straight face, it is initially only possible for the sole-retainer (33, 34, 35, 36), to perform a movement transversely to the longitudinal direction of the ski.

In this case, the returning element is a thrust spring 50 which engages through angle arms 39, 40, which are mounted to pivot about pin members 43, 44, against the bolt 32 and thus against the sole-retainer 33, 34, 35, 36.

Theangle arms 39, 40 are inserted in a recess 53 in the fixed part 30 and, in the starting position, bear against the shoulders 45, 46 of the recess 53. Sothat tilting of the spring 50 out of the position between the angle arms 39, 40 is avoided, a spring guide41, 42 is provided on each of the arm ends.

During a lateral movement of the sole-retainer 33, 34, 35, 36, the spring 50 is in each case compressed by one of the angle arms 39, 40. The increasing springforce is however largely compensated by the altered line of force action. Since, with increasing pivoting, the spring force acts through'the angle arm 39, 40 still more slantwise on the bolt 32, so an ever-increasing force must be applied in this inclined direction in order to obtain a transverse force which is for example constantin any position.

With this embodiment, too, the spring element remains engaged even after release, so that an independent reutrn of the sole-retainer 33, 34, 35, 36 from any pivoted position is ensured.

FIGS. 7-9 show a further embodiment according to the invention. In this case, the housing 60-is mounted rigid on the ski, the sole-retainer 79 being guided in a groove 76 of the sliding block 75 which, for its part, can only move transversely to the longitudinal direction of the ski, through the guide 61. The sole-retainer 72 is braced through the roller 73 and its spindle 74 against the guide face 66 of the housing 60. During absorption and damping of forces arising transversely to the longitudinal direction of the ski, the sole-retainer. 72 first has,

to execute a purely transverse movement due to the guide 61 of the sliding block 75 and the guide 66 of the housing 60, against which the roller 73 rolls. Only after a certain transverse path has been travelled does the roller 73 of the sole-retainer 72 leave the guide surface 66, making it possible for the sole-retainer, through the sloping faces 64 and 65, to enter the recesses 63 or 62 of the housing 60, allowing the sole-retainer 72 to perform a forward movement, releasing the foot. So that a spring force can be used to counteract the lateral movement, a thrust spring 68 is provided which engages the curve 77 of the sliding block 75 through a pusher. 69 in which the roller 70 is mounted by means of pin member 71. The setscrew 67 is used to pre-tense the spring 68 as necessary. During a lateral movement of the sliding block and, with it,

of the sole-retainer 72, the roller 70 rolls along the curve 77 and so presses the spring 68 additionally together. The curve 77 must therefore be so shaped that, by changing the point of attack of the force on the roller 70, the increasing spring force can be so compensated that a transverse force which is the same for example in any position, .acts on the sole-retainer 72.

As can be seen from FIG. 9, the returning element 67-71 remains engaged with the curve 77 even in the released position, so that an automatic return of the soleretainer 72 into the starting position is still guaranteed.

We claim:

1. A toe iron for safety ski binding comprising a base means attached to a ski, said base means being formed with a guide surface extending transversely to the longitudinal direction of the ski, the length of which corresponds approximately to the range of foot-twist occurring during harmless lateral jolts, and terminating in guide faces which are inclined sharply forwardly to said transverse guide surface, a sole-retaining member carried by said base means, said sole-retaining member being positioned for movement along said guide surface and being biased by a return spring means carried by said base means and acting upon said sole-retaining member in every position to bias the sole-retaining member towards its normal sole-retaining position.

2. A toe iron according to claim 1, characterized in that said spring means includes a pair of resiliently pivotable arms, and the sole-retaining member includes an abutment part which moves against the force of the resiliently pivotable arms, the design and arrangement of each arm compensating for increased resistance during pivotal movement.

3. A toe iron according to claim 1, characterized in that the spring means cooperates with the sole-retaining member through a control curve provided thereon, the control curve being so constructed that a corresponding lessening of curve pitch matches increase in spring resistance.

4. A toe iron according to claim 1, characterized in that said spring means includes a pair of pivotal arms, one ends of which are biased by a spring and the other ends of which cooperate with the sole-retaining member, said arms being so constructed that increase in spring resistance is compensated by altered line of force.

5. A toe iron according to claim 2, characterized in that the spring means is comprised of a torsion spring, the free spring ends of which are shaped as lever members and cooperate with a corresponding abutment part of the soleretaining member.

References Cited UNITED STATES PATENTS 3,079,164 2/1963 De Place 280l1.35 3,224,786 12/1965 Tosalli 2801l.35

BENJAMIN HERSH, Primary Examiner. JAMES H. BRANNEN, Assistant Examiner. 

1. A TOE IRON FOR SAFETY SKI BINDING COMPRISING A BASE MEANS ATTACHED TO A SKI, SAID BASE MEANS BEING FORMED WITH A GUIDE SURFACE EXTENDING TRANSVERSELY TO THE LONGITUDINAL DIRECTION OF THE SKI, THE LENGTH OF WHICH CORRESPONDS APPROXIMATELY TO THE RANGE OF FOOT-TWIST OCCURRING DURING HARMLESS LATERAL JOLTS, AND TERMINATING IN GUIDE FACES WHICH ARA INCLINED SHARPLY FORWARDLY TO SAID TRANSVERSE GUIDE SURFACE, A SOLE-RETAINING MEMBER CARRIED BY SAID BASE MEANS, SAID SOLE-RETAINING MEMBER BEING POSITIONED FOR MOVEMENT ALONG SAID GUIDE SURFACE AND BEING BIASED BY A RETURN SPRING MEANS CARRIED BY SAID BASE MEANS AND ACTING UPON SAID SOLE-RETAINING MEMBER IN EVERY POSITION TO BIAS THE SOLE-RETAINING MEMBER TOWARDS ITS NORMAL SOLE-RETAINING POSITION. 